¶ … philosophical approaches to the study of equality presume that equality is an ideal, and suggest methods by which to achieve maximum equality. However, some philosophical approaches deny the inherent value of equality or an egalitarian society. All philosophical viewpoints relate equality to morals or ethics, primarily because equality is deemed an ethical objective. Using a utilitarian philosophical perspective, equality is an ethical ideal that presumably maximizes happiness for the greatest number of people. A deontological ethical perspective would similarly note that equality is an ethical ideal, not necessarily because it leads to a consequence like happiness, but because equality is inherently good. "Equality is a contested concept" in philosophy and politics, but equality is actually fundamental to all practical applications of political philosophy (Dworkin, 2002, p. 2). Decisions made about things like taxes or due process of law hinge on a theory of equality. Similarly, access to health care, education, and other services considered essential depend on whether the people of a society value equality. Applying ethical theories to the concept of equality can help to define terms and therefore clarify the concept of equality as an ideal.

As Sen (1979) points out, there are three basic types of equality from a philosophical standpoint, including utilitarian equality, total utility equality, and Rawlsian equality. These are not necessarily mutually distinct views on equality, as there is considerable overlap in their approaches. Utilitarian equality is complex, but basically refers to equality as a means to an end. On the other hand, total utility equality and Rawlsian equality suggest that equality is the end in itself. Gosepath (2007) outlines several more essential categories of equality including formal equality, proportional equality, and moral equality. Formal equality is literally referring to equality of form, such as two people having the exact same talents and even biology, such as twins. Proportional equality acknowledges diversity, while still affirming equality of consideration, such as two siblings who are a year apart, one of which excels in math and the other in writing. Moral equality refers to the equal moral consideration due to all persons, regardless of their circumstances or even their actions.

Equality can be most simply discussed in terms of equality of opportunity vs. equality of outcome. Equality of opportunity is a purported ideal in democratic societies, which encourage competition and a sort of Darwinian rising to the top of those who either try harder or have innate abilities that distinguish one person from the next. Also referred to as a meritocracy, this view avows the potential for inequality of resource distribution. Using this viewpoint, equality of outcome is often considered unattainable given limited resources or human nature. Some philosophical viewpoints prior to the modern era were not rooted in the fundamental assumption that all human beings are worthy of equal consideration. In fact, patriarchal and racist philosophies are by definition based on the preference for inequality as both a means and as an end. No one ethical theory can address all aspects of equality; rather each perspective sheds light on the value of equality, the role equality plays in human societies, and the methods by which equality can be attained.

Equality is frequently conceived of as referring to essential equality of all human beings, based on "a background idea that all human persons are equal in fundamental worth or moral status," (Arneson, 2013). This view, that all human persons are equal in fundamental worth and moral status, is also known as natural equality and has roots in Stoic and Christian philosophical discourse (Gosepath, 2007). The implications for this type of natural equality is in the realm of justice; if all human persons are deemed equal in fundamental worth or moral status, then there should theoretically be no such thing as preferential treatment or discrimination. In this sense, formal equality is similar to natural equality. However, there are different types of equality. For instance, factors that mitigate equality within some philosophical frameworks include gender, race, social class status, and genetics. The "separate but equal" fiasco that was a long part of American history shows how easily it can be to conflate equality with subordination. When a group in power makes the laws, they can project their version of equality onto others. It is more rightfully supposed that, as Hobbes put it, "in their natural condition, individuals possess equal rights, because over time they have the same capacity to do each other...

Equal rights are often stripped away by the law or under common agreement in social bonds, such as when convicted felons are not treated equally as a person who has never been convicted of a crime. From a utilitarian standpoint, it makes sense to create inequalities as a form of retributive justice because it promotes law and order in society and ensures conformity with social norms. Theoretically, punishments are equally meted out so that any person who commits a crime will receive the same treatment. This may not hold true in practice, but the philosophical theory is that each person starts off with the same moral consideration and the same ethical duties.
Although most rational philosophies would posit that each person is equally deserving of human rights than any other, equality does not necessarily entail sameness. Two things that are exactly the same would be presumed already to be equal, which is why the concept of equality is most important when it refers to things that are different. As Gosepath (2007) puts it, equality refers to the "qualitative relationship" that exists between two or more objects or beings. Given that the world is comprised of diverse beings with diverse needs, abilities, interests, aptitudes, goals, and values, equality cannot be defined as sameness. As Dworkin (2002) puts it, a "flat, indiscriminate equality is not just a weak political value…it is no value at all," (p. 2). Equality must be defined more in terms of equality of opportunity or equality of outcome.

Consequentialist ethical theories like utilitarianism can focus on both equality of opportunity and equality of outcome. Utilitarianism presumes that all beings are equally motivated to be happy, thereby providing a unifying ground upon which to discuss the concept of equality. Even if there are vast differences between people, the desire to be happy remains universal. Based on this assumption, it becomes a moral imperative to promote the greatest level of happiness for the greatest number of people. It then becomes necessarily to determine how to equitably distribute limited resources to ensure maximum happiness for the greatest number of people. A socialist political and economic system would hold that every person should be guaranteed equal opportunity to pursue any chosen path to happiness, so long as that pursuit does not hinder the rights or happiness of others. "Equal opportunity" has in fact become a phrase used in public policy such as in "equal opportunity employment." Equality of outcome refers to equitable distribution of resources, such as equitable wealth distribution to equal pay for equal work. Whereas the United States generally professes to be the land of equal opportunity, it is not a nation that believes in equitable wealth distribution and is likewise not committed to ensuring equality of outcome in terms of ensuring gender and race equity. Thus, the American brand of equality is philosophically rooted more in equality of opportunity than of the equality of outcome.

Not everyone is born equal, but everyone has equal right to pursue happiness, and to have access to equal rights. Perceived inequalities emerge when people born with specific talents win competitions or have better-paying jobs than people without such talents. There are two main ways of looking at the nature of luck in the theories of equality. One way of looking at luck is to suggest, as Rawls did, that it makes sense to equitable distribute resources to make up for the fact that some people were born with bad luck circumstances (Rodrigues, 2014). This point-of-view forms the basis of many of the socialist political philosophies, which avow the utilitarian or deontological importance of reducing income disparities and other disparities of resources -- either to ensure the greatest good for the greatest number (the utilitarian approach) or because it is a moral imperative for those with an excess of resources to create balance by helping those with deficiencies. The Rawlsian point-of-view on equitable distribution of resources is based in turn on the principle of marginal utility. Marginal utility is the value of a resource in terms of its bestowing happiness. "The marginal utility of a resource for a person is the difference in that person's happiness that an additional unit of the resource will make. The principle of declining marginal utility says that the marginal utility of a resource for a person declines the more of that resource the person already has," (Sensat, n.d., p. 1). In other words, a rich person will not miss five dollars as much as a poor person will because for the rich person, five dollars has less marginal utility than it has for the poor person.…